1. Field of the Invention
The present invention relates to a dishwasher, and particularly, to a filter for a dishwasher capable of filtering foreign materials.
2. Background of the Invention
In general, a dishwasher is a device to automatically wash dishes, configured such that dishes to be washed up are put on a tub and water is injected onto the dished through a plurality of nozzles disposed at the tub so as to be washed up. Afterwards, foreign materials washed out of the dishes are filtered by a filter assembly installed on the bottom of the tub and water having such foreign materials separated therefrom drains outside.
FIG. 1 shows a general filter assembly. As shown in FIG. 1, a filter assembly 5 includes a filter frame 11, a circulation filter 12 installed inside the filter assembly 5 and having a plurality of filtering openings 12a to filter small (tiny) foreign materials off, a drain filter 13 disposed parallel with the circulation filter 12 and having a plurality of mesh openings 13a to filter large foreign materials off, and a handle 14 which user grasps.
A user grasps the handle 14 to put a filter frame 11 on a filter groove (not shown) formed at the bottom of a tub, so as to complete the installation of the filter assembly 5.
With such configuration, water from which small foreign materials are filtered off through the filtering openings 12a is circulated to dishes to be washed up, and water from which large foreign materials are filtered off through the mesh openings 13a are thrown away to the outside.
Meanwhile, the filter assembly 5 includes inside the filter frame 11 both the circulation filter 12 which filters small foreign materials and the drain filter 13 which filters large foreign materials, the circulation filter 12 and the drain filter 13 being parallel with each other. Accordingly, a filtering area of the circulation filter 12 is relatively determined depending on a filtering area of the drain filter 13. Hence, the circulation filter 12 cannot be installed at the entire area inside the filter frame 11, which causes the circulation filter 12 to have a smaller filtering area. Accordingly, if foreign materials cover all over the small filtering area of the circulation filter 12, the circulation filter 12 can be blocked. In addition, the amount of water circulating through the circulation filter 12 is decreased, possibly resulting in a degradation of an efficiency of water circulation.
It is sure that water having foreign materials filtered off through the drain filter 13 can further be filtered and joins water filtered through the circulation filter 12, thus to be supplied onto dishes to be cleaned.
To this end, in case where both the circulation filter 12 and the drain filter 13 are installed at the filter groove, a plurality of communication holes acting as filters are formed through a partition wall interposed between the circulation filter 12 and the drain filter 13. However, such communication holes allow the increase in the filtering area in which foreign materials contained in water circulating through these communication holes can be filtered off; however, the drain filter 13 only filters large foreign materials, whereby foreign materials failed to be filtered by the drain filter 13 can block the communication holes. Hence, it is difficult to expect a filtering effect through the communication holes.